PTL 1 describes an example of a system for controlling a multilayer network. A policy-based communication management system in PTL 1 includes, in each layer of a communication network constituted of a plurality of access networks and a core network: a means that stores a management policy; and a policy management means that manages a layer in accordance with the management policy. Further, in the policy-based communication management system, the policy management means searches for the management policy upon occurrence of an event on a layer. The policy management means includes: a means that issues an action request to a policy management means on a server layer while assuming that the own layer serves as a client and the other layer serves as the server layer, when an action of a management policy matching with a condition of the event is not an action of the own layer. The policy management means further includes: a means that returns a response to an action request to a policy management means on a client layer, when the action is not an action of the own layer as a result of searching for the management policy by the policy management means having received the action request as a server layer. The policy management means further includes: a means that performs policy management in accordance with the management policy of the own layer, when being notified of an execution result of an action request from the other layer.
PTL 2 discloses a virtual network connection device that is expected to be able to facilitate setting work in connecting two virtual networks. PTL 2 discloses a method of copying mapping information indicating a correspondence relationship of a virtual link between two virtual networks and physical interface information associated with the virtual link and rewriting the mapping information as needed. The method thereby facilitates setting of a control device controlling a virtual network to be connected.